Output cabling of a high voltage surge tester of coils is critical in maintaining a slope of a leading edge of a surge waveform over distances of more than a few feet. When using discreet wiring with high voltage insulation for the output cabling, a potential for a significant change to mutual inductance of the discreet wiring exists (particular, when transmitting a fast rise time into an inductive load, such as the coils). Yet, because the high voltage surge tester does not employ any impedance matching network (between the high voltage surge tester and the coils), a current oscillation in contemporary implementations of the output cabling can occur that will change the slope on the surge waveform. This change in the slope causes difficulties in maintaining rise times. In turn, test leads of the high voltage surge tester must also be kept short.